Fix the Linux driver so that it doesn't use 5-15% CPU when my DisplayLink device is _unplugged_.
When unplugged, I consistently (and continuously, not just short spikes) see the DisplayLinkManager process take up 5-15% CPU. I don't understand why it's using so much CPU when there's literally nothing for it to do. It's really hurting my battery life & performance.
DocWilco
shared this idea
This should now be fixed in Ubuntu release 1.2 available from our website:
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Aftab Naveed
commented
This seems to be not fixed, DisplayLink manager is still most power consuming process even when I have no display attached.
mmary: 6635.1 wakeups/second, 0.0 GPU ops/seconds, 0.0 VFS ops/sec and 126.7% CPU use
Usage Events/s Category Description
31.9 ms/s 1693.4 Process [PID 29086] /opt/displaylink/DisplayLinkManager -
Wouter Bolsterlee
commented
i also suffer from this. displaylinkmanager drains my battery when NO external screen is connected. strace reveals a lot of select() syscalls with a 0 timeout. is that really needed?
[pid 3436] nanosleep({0, 1000000}, NULL) = 0
[pid 3436] select(10, [5 9], NULL, NULL, NULL) = 1 (in [9])
[pid 3436] write(15, "\n", 1 <unfinished ...>
[pid 3438] <... select resumed> ) = 1 (in [10])
[pid 3436] <... write resumed> ) = 1
[pid 3438] futex(0x24636f0, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 3436] futex(0x24636f0, FUTEX_WAKE_PRIVATE, 1 <unfinished ...>
[pid 3438] <... futex resumed> ) = -1 EAGAIN (Resource temporarily unavailable)
[pid 3436] <... futex resumed> ) = 0
[pid 3438] read(10, <unfinished ...>
[pid 3436] nanosleep({0, 1000000}, <unfinished ...>
[pid 3438] <... read resumed> "\n", 1000) = 1
[pid 3438] futex(0x24636f0, FUTEX_WAKE_PRIVATE, 1) = 0
[pid 3438] select(10, [9], NULL, NULL, {0, 0}) = 1 (in [9], left {0, 0})
[pid 3438] read(9, "", 1) = 0
[pid 3438] access("/tmp/PmMessagesPort_in", F_OK) = 0
[pid 3438] select(14, [10 11 13], NULL, NULL, NULL <unfinished ...>
[pid 3436] <... nanosleep resumed> NULL) = 0